a). Field of the Invention
The invention relates to the focusing of microscope objectives and, in particular, a device for switching and focusing microscope objectives.
b). Description of the Related Art
Conventional microscopes which operate on the principle of focusing the objective turret instead of the microscope stage are often used for micromanipulation of the specimen (patch clamp technique) and for electrophysiological measurements. The specimen is held in various vessels for this purpose. These vessels are often Petri dishes with projecting edges. The specimen is placed in aqueous solution.
As a rule, two objectives are sufficient for searching and observation. Problems occur when changing the specimen vessel, when displacing the microscope stage and when switching the objective into the work position. The circular arc-shaped movement of the objectives when switching a conventional objective turret can result in contact with the highly sensitive manipulators. It is possible under some circumstances for the objective to strike the edge of the Petri dish, which causes the specimen to be moved at least in its x,y position. During the usual diagonal deflection of the objective (switching to the next objective), the liquid is moved in the horizontal direction, which can also result in the problem described above.